Internal combustion engine and control apparatus



y 1942- H. OSWALD 2,281,987

INTERNAL COMBUSTION ENGINE AND CONTROL APPARATUS Filed Oct. 28, 1937 2Sheets-Sheet l 71/ m J BLOWER 76 f2 7 35a 24 F051 Par/p gag/m0? gh Q1 353 /0 MK, 3.9K, J1 IL 3 \h J I 442:9 3 A Q C) 139 43 4, 34; 6a a no; r 7{M 7 i 1 I 6 4 0 5 26 J2 33 L7 4 /51?! [fa F051 amp INVENTOR I 7 0l7505mm WYQMWM 1 51mm ATTORNEYS H. OSWALD 2,281,987

May 5, 1942.

INTERNAL COMBUSTION ENGINE AND CONTROL APPARATUS 2 Sheets-Sheet 2 FiledOct. 28, 1937 INVENTOR ATTORNEYS Patented May 5, 1942 INTERNALCOIVIBUSTION ENGINE AND CONTROL APPARATUS Hans Oswald, Winterthur,Switzerland, assignor to Sulzer Freres, Societe Anonyme, Winterthur,Switzerland Application October 28, 1937, Serial No. 171,416 InSwitzerland November 7, 1936 8 Claims.

This invention relates to control apparatus for internal combustionengines of the kind to which air is supplied by a supercharger.

The object of the present invention is to provide in combination with aninternal combustion engine to which air is supplied by a supercharger,control apparatus which, when the supercharging pressure reaches a'predetermined value, automatically prevents a rise in superchargingpressure above that value. Thus, as the altitude at which the engineoperates is decreased and the barometric pressure rises, a point occurswhen the predetermined superchargin pressure is reached whereupon onfurther reduction in altitude and increase in barometric pressure, thecontrol apparatus prevents a further increase in the superchargingpressure and thus maintains this supercharging pressure constant.

Means may also be provided whereby, for supercharging pressures belowthe predetermined value, the control apparatus acts to regulate thequantity of fuel delivered to the engine in dependence on thesupercharging pressure.

The control of the supercharging pressure may be effected in variousways. In one arrangement, however, wherein the supercharger is driven byan exhaust-driven turbine or like device deriving power from the exhaustgases, the supercharglng pressure may be controlled by valve apparatuscontrolling the proportion of exhaust gases which pass respectivelythrough the exhaust-driven turbine and direct to the atmosphere withoutpassing through such turbine.

In an alternative arrangement the supercharging pressure may becontrolled by permitting part of the air delivered by the superchargerto be discharged to the atmosphere through a valve under the control ofthe control apparatus.

- In the drawings:

Fig. 1 shows curves indicating variations of barometric pressure, ofcharging pressure and the load of the engine;

Figs. 2 and 3 illustrate the two embodiments of apparatus in accordancewith the invention;

Fig. 4 is an enlarged fragmentary sectional view of a part of theapparatus of Fig. 3;

Fig. 5 is an enlarged fragmentary sectional view of another part of theapparatus of Fig 3; and- Fig. 6 is an enlarged fragmentary sectionalview of a part of the apparatus of Fig. 2.

In Fig. 1 line a. represents the average barometric pressure as afunction of the height above sea level from O to C, the line b thecharging pressure, that is to say, th pressure of the air entering intothe internal combustion engine, and the line 0 the load of the internalcombustion engine. With decreasing elevation from C to O the averagebarometric pressure a rises continuously, With a uniform volume ofexhaust gas discharged by the engine and driving the supercharger, thepressure of the charging air also increases slightly. If, as shown byline 0, the load of the engine increases then the pressure of thecharging air, as shown by line b, increases. If the load on the engineis kept constant from B to 0 then the rise in the charging air pressureis less and the line b is flatter from B to 0 than from C to B. At A thechargin pressure b reaches the permissible maximum. Then a regulatingdevice comes into operation which automatically maintains constant thecharging pressure from this definite adjustable value on.

The apparatus illustrated in Figs. 2 and 3 is especially intended for thoperation of highway or railroad vehicles over widely varying altitudes.

In the apparatus of Fig. 2 the internal combustion engine I drives thegenerator 2, theexcitation of which is automatically regulated by meansof the servomotor 3 and the resistance 4. The speed governor 5, drivenby the internal combustion-engine, regulates by means of the rod 6 theamount or fuel injected by the fuel pumps I and also by means ofthe'valve 8- of the servomotor 3 the excitation of the generator 2 sothat the speed of the internal combustion engine I and its output aremaintained constant in the conventional manner. The rod 6 and the valve8 are connected together and move as a unitary element. As the speed ofthe engine decreases, the governor moves the rod 6 and the valve 8 tothe left.

The exhaust gases of the internal combustion engine are led by means ofthe pipes 9 to the exhaust gas turbine III, which drives the blower II,and conveys the charging air into the charging pipe l2. The regulatingdevic l3 has a chamber [5 connected to the chargin pipe 12 by means ofthe pipe ll, in which chamber is located the aneroid member IS, on whichthe charging pressure acts from theoutside. The aneroid member I6 issealed and the space-therein is not open to the atmosphere.

One end of the valve I1 is connected to the aneroid member I and theopposite end carries a plate or stop l'la mounted in a casing [8 whichcasing is attached to the end of rod ID. 'A spring 23 is mounted in thecasing and arranged to exert pressure against the casing and the stopHe. The rod I8 is connected to the lever which displaces theintermediate sleeve valve 2| so that to'every absolute charging pressurethere corresponds a definite load of the internal combustion enginemaintained constant by the servomotor 3. As the piston |1 moves to theleft is compresses the spring 23 until it pulls the casing |8 intoengagement with the stop 22. The piston |1 continues to move to the leftafter the casing l8 and rod l8 have reached their limit of movement tothe left.

If the barometric pressur and the charging pressure gradually rise, (e.g. as shown in Fig. 1 from C to B), then the pressure in chamber l5collapses the aneroid member l6 and causes the rod I8 and the sleevevalve 2| to move toward the left so that the shut-off position of thevalve 8 is likewise displaced toward the left. On the movement of sleevevalve 2| toward the left, pressure medium is admitted to the right sideof the piston 3a of the servomotor 3, so that by the displacement ofthis piston toward the left the resistance 4 is lessened. As aconsequence of this, the engine is mor heavily loaded by the generator 2as the voltage thereof is increased.

As the speed of the internal combustion engine decreases and thegovernor 5 displaces the regulating rod 8 toward the left, the pumps 1supply more fuel to the engine and the, valve 8 comes into the shut-offposition, displaced toward the left, until the new load corresponds tothe new position of the sleeve valve 2|.

The load now increases according to the line (2 in Fig. 1 until at B ithas reached the, maximum permissible value. At this moment, the casingll strikes on the stop 22. On the further movement of the valve l1toward the left, which now is disconnected from the rod l8 undercompression of the spring 23, no further influence on the load takesplace. In this position the valv |1 still keeps open the flow ofpressure medium to the space at the right of the piston 24 and connectsthe space at the left of this piston to the discharge so that piston 24remains in the extreme left position. v

If the barometric pressure rises further, then the charging pressurelikewise increases from B to A. At A the aneroid member I8 is compressedtosuch an extent that the valve l1 begins to regulate the position ofthe piston 24. The piston 24 keeps closed, in its left end position viathe rod 25 and crank 25a, the flap valve 26 in the exhaust gas line 8.If the valve l1 moves to the left beyond the shut-off position, then theflow of pressure medium on the left side 'ofthe piston 24 is opened andthe right side is connected to the pressure medium discharge.Simultaneously the flap valve 28 is opened but only so much until thecharging pressure in the charging pipe |2 has again fallen to the valuecorresponding to the shut-off position of the valve l1. Thereby thecharging pr ure will then be maintained constant on furt er increasingbarometric pressure, inasmuch as the flap valve 28 opens further andallows more exhaust gases to flow out. In the case of decreasingbarometric pressure the regulating operations described proceed in theopposite sense.

The apparatusshown in Figs. 3, 4 and 5 comprises an internal combustionengine driving of the engine and has a rod 5a attached at one end to thevalve 8 and at the other end to the case 34a of the resilient coupling34. The spring 341) presses against the case on th right side andagainst the stop 340 on the end of the fuel pump rod 33. spring plate 31against which the-spring31a exerts pressure.

34b, thereby urging the stop 34c and rod 33 toward the left increasingthe supply of fuel. In this action, the spring 31a urges the rod 33towards the left. The limit of motion is reached when the plate 31contacts the stop 38. On the other hand an increase in the speed of theengine will move the rod 511 and case 34a towards the right until itengages the stop 34c pulling the rod 33 to the right and against theaction of spring 31a. It will be noted that the movement of the rod 5awill so set the valve 8 when the speed of the engine is increasing ordecreasing as to admit fluid pressure against the piston 3a of theservomotor 3, thereby decreasing or increasing the field resistance 4.Whenever equilibrium is reached with respect to the load and enginespeed, the valve 8 returns to the neutral position shown in Fig. 3.

The exhaust gases of the engine are discharged into the manifolds 8 andfrom there pass through and operate the gas turbine l8 which-drives thesupercharging blower II, which charges air into the engine cylindersthrough the chargin pipe l2. The charging pipe I2 is connected by pipe Hto a regulating device comprising an aneroid chamber IS in which ismounted the aneroid member IS. The aneroid member I6 is sealed so thatgas cannot enter it and is expansible or collapsible depending upon thepressure within the chamber I5. The servomotor 28a has a piston valve 28controlling the supply and discharge of fluid to operate the piston 38.The rod lia which reciprocates under the action of the aneroid member |8is connected toja slot in the lever 21 and the valve- 28 is connected toan intermediate slot in the lever 21. One end of the rod 28 is connectedto the lever 3| at an intermediate point and the other end i connectedto rod 28b (see Fig. 4) which is attached to bracket 30a. The spring 30bpresses against the bracket 30a at one end and against the sleeve 48a atthe other end. The lever 21 is pivoted at 4| to the sleeve 48a which isfree to slide towards the left compressing the sprin 30b under theaction of rod 28 pressing against the face of the sleeve 48a. When thepiston 30 is moved towards the right the spring 30b causes the sleeve48a to follow the rod 28 until the sleeve 40a contacts the flanged edgeof the servomotor as shown in Fig. 3. The rod 28 and piston 38 are freeto' finish their movement toward the right without further affecting themovement of lever 21. The lower end of the-lever 3| has a stop 32arranged to engage the rod 33 and force it towards the right, therebycompressing the springs 34b and 31a. The upper portion of the lever 3|has a roller link 35in the slot 36 of the rod 38 which is attached atone end to the bell crank 38a. One extremity of the bell crank isattached to a rod 38b which is arranged to open and close the flap valve40 in the charging pipe |2 to regulate the volume of air chargedtherethrough from the blower The lever 21, sleeve 4|a, rod 28, lever 3|,rods 38 and 33 comprisea slip-motion coupling or linkage.

The left end of the rod 33 has a Upon decrease of engine speed, 'the rod5a moves the case 34a against the spring With very low charging pressure(point C in Fig. 1) the control valve 28 is in the right end position,whereby the piston 30 assumes a left end position. The upper link 35 ofthe lever 3| works freely in the slot 36. The lower end presses the stop32 on the rod 33 and limits the fuel supply to the minimum value.

If now the charging pressure increases, the valve 28 is first broughtinto its shut-off position, then beyond it toward the left, and allowsoil to enter at the left of the piston 30. As a consequence of this thepiston 30 moves toward the right, does not yet influence the rod 39 bymeans of the slot 36 for the moment, but pulls the stop 32 back a littleso that the supply of fuel is slightly increased. The follow-up lever 21brings the valve 28 again into the shut-oil? position.

If the charging pressure increases further, the same action or operationis repeated anew. With the charging pressure corresponding to the pointB in Fig. l the spring plate 31 engages the stop 38 so that in spite offurther turning of the lever 3| in clockwise direction the fuel nolonger increases. If the charging pressure increases further, then thepiston 30 moves further toward the right, and the lever 3| at a givenmoment takes the slot 36 along; thereby the valve 40 in the chargingpipe I2 is opened by means of the rod 39, to let out a part of the airconveyed by the charging compressor. Simultaneously the sleeve 4| of thelever 21 strikes on the casing of the servomotor 28a so that the returnis suppressed. If the charging pressure rises still further, the valve28 allows so much pressure medium to gain admission to the piston 30that the valve 40 is opened so wide the pressure falls to the valuecorresponding to'the shut-off position of the valve 28.

The sequence of the different events in Fig. 1 represents simply anexample. It is also possible. that the output of the internal combustionengine remains constant in the whole range from C to 0, so that adecrease of the amount of fuel and of the load occurs only when thecharging group no longer works normally.

I claim:

1. The combination with an internal combustion engine which comprises aturbine driven by the exhaust gases from the engine, a blower driven bythe turbine for charging air into the engine, a regulating deviceoperatively connected to the blower responsive to the charging airpressure, a fuel-supply means for the engine, a speed governor driven bythe engine, a variable load driven by the engine, a servomotor forvarying the load, means operatively connecting the governor to theservomotor and to thefuelsupply means for simultaneously increasing thefuel and decreasing the load as the speed'of the engine decreases andsimultaneously decreasing the fuel and increasing the load as the speedof the engine increases,'wher eby the speed of the engine and its outputare maintained constant, and means operatively connecting the regulatingdevice" to the servomotor for adjusting the opening and closingpositions of the servomotor so that for every charging air pres-' surethere corresponds a definite load of the engine maintained constant bythe servomotor.

2. The combination with an internal combustion engine which comprises ablower for charging air into the engine, an aneroid member actuated bythe pressure of the charging air, a valve for increasing or decreasingthe pressure of the charging air, means connecting the aneroid member tothe valve, whereby an increase in charging air pressure'above apredetermined high pressure will cause the aneroid member to actuate thevalve to decrease the charging air pressure, a variable load driven bythe engine, a fuel-supply'means for the engine, a speed governor drivenby the engine connected to the fuel-supply means for increasing ordecreasing the fuel supplied to the engine as the speed of the enginedecreases or increases, a re-' silient coupling, means forvarying theload on the engine connected through the resilient coupling to theaneroid member, means connecting the governor to the means for varyingthe load, whereby at low charging air pressures the aneroid memberadjusts the means for varying the load under the action of the governor,and at high charging air pressures the aneroid member does not adjustthe means for varying the load but begins to actuate the valve toincrease or decrease the charging air pressure.

3. The combination with an internal combustion engine which comprisesmeans for charging .air into the engine, valve means for regulating thecharging air pressure, a regulating device actuated by the pressure ofthe charging air, a variable load driven by the engine, means forvarying the load, a fuel-supply means for the engine, a speed governordriven by the engine arranged to operate the means for varying the loadand the fuel supply means, whereby the fuel supply and the load may beincreased or decreased by the governor, and means operativelyinterconnecting the regulating device, the valve means and thefuel-supply means which permits, at low charging air pressure, theregulating device to limit the fuel to a minimum value without operatingthe valve and, at higher charging air pressures, to operate the valve tobustion engine which comprises means for charging air into the engine,valve means for regulating the pressure of charging air, a fuelsupplymeans for the engine, a regulating device actuated by the pressure ofthe charging air, a servomotor under the control of the regulatingdevice, linkage means operatively interconnecting the servomotor, thefuel-supply means and the valve means, and means operating through saidlinkage means permitting the servomotor to limit the fuel supply whenthe charging air pressure is low independently of the valve means and tooperate the valve means to decrease the charging air pressure when thecharging air pressure is high independently of .the fuel-supply means.

speed increases and to increase the fuel supply as the engine speeddecreases, a variable load connected to and driven by the engine, meansfor varying the load, means connecting the governor to the means forvarying the load to increaseor decrease the load as the speed of theengine increases or decreases, a regulating device connected by conduitto the supercharger, whereby the regulating device is actuated by thepressure of the charging air, valve means conber whereby the regulatingdevice may limit the supply of fuel when the charging air pressure islow and control the valve to decrease the charging air pressure when thecharging air pressure is high independently of the fuel-supply means.

6.'The combination with an internal combustion engine which comprisesmeans for charging fuel into the engine. means for charging air into theengine, a regulating device responsive to changes in the pressure of thecharging air connected by conduit to the means for charging air, meansoperated by the regulating device controlling the pressure of thecharging air, a variable load driven by the engine, load control means,a governor driven by the engine arranged to vary the load control meansand the means for charging fuel simultaneously, and coupling meansconnecting the regulating device to the load control means which permitsthe regulating device to influence the action of, the governor when thecharging air pressure is low and to act independently of the loadcontrol means when the charging air pressure is high.

-'l. The combination with an internal combustion engine which comprisesmeans for supplying fuel to the engine. means for charging air into theengine under pressure, a regulating device responsive to the chargingair pressure connected by conduit to the means for charging air, a valvein the means for charging air for decreasing the charging air, pressurewhen the I charging air pressure is high, said valve being operativelyconnected to and actuated by the regulating device, a governor driven bythe engine arranged to increase or decrease the supply of fuel in accordance with engine speed, and means connecting the regulating device tothe means for supplying fuel which limits the supply of fuel when thecharging air pressure is low.

a. The combination with an internal combus tion engine which comprisesmeans for charging air into the engine, said engine being provided withmeans to drive a variable load, a governor driven by the engine,/aregulating device responsive to the pressure of the charging air, meansin operative association with the regulating d vice and the governor forcontrolling the load in accordance with engine speed and the pressure ofthe charging air, and a valve for controlling the pressure of the aircharged into the engine, said valve being operatively connected to andactuated by the regulating device.-

- HANS OSWALD.

